UC Santa Cruz

Sunlight powers all living things on earth, either directly or indirectly. Plants use light for photosynthesis and pass on the energy to animals that consume them. In order to use light to manufacture food or signal other processes, living beings have to sense and react to light and they do this with a variety of photoreceptors that are sensitive to different spectrum of light. Many studies have been done on the plant photoreceptors and although the list is still incomplete, several have been identified and characterized. Phytochromes absorb mainly red/far-red light with some shown to even respond to UV-A/blue light. The main purpose of this study is to focus on blue light sensing segment of phototropin called LOV2 (in plants) and simply LOV domain in bacteria. We follow the light activation of LOV-HTH domain of Erythrobacter Litoralis bacterium and follow the events upon light activation using many spectroscopic tools available to study such event. It is the aim of this study to show that upon light activation, movement of a segment of this molecule causes LOV domain to activate the effector domain downstream. The kinetics of adduct formation and dark state relaxation of the other two LOV domains in this bacterium named EL346 and EL368 are also studied.